Effect of arginine:lysine and methionine source on amino acid digestibility and response to dietary electrolytes in chronically or acutely heat-stressed broilers

Abstract

Gonzalez-Esquerra, R. and Leeson, S. 2006. Effect of arginine:lysine and methionine source on amino acid digestibility and response to dietary electrolytes in chronically or acutely heat-stressed broilers. Can. J. Anim. Sci. 86: 263-271. In two experiments, the effects of arginine:lysine, NaHCO 3 and methionine source on performance and amino acid digestion of heat-stressed broilers were studied. In exp. 1, corn/soy diets with argine:lysine (Arg:Lys) of 1.10, 1.25 and 1.40 were fed from 21 to 42 d. Diets were supplemented with 2-hydroxy-4-(methylthio)-butanoic acid (HMB) or DL-Methionine (DLM) with NaHCO 3 at 0 or 1.04%. Ten replicates per treatment of four birds per cage were maintained at 31.7 ± 0.9°C. From 21 to 28 d weight gain (BWG), feed consumption and feed-to-gain (FCR) were unaffected by diet treatment. Methionine source did not influence bird performance (P > 0.05). However, from 35 to 42 d, when diets were supplemented with NaHCO 3 , BWG and FCR of birds fed DLM were compromised when offered diets with Arg:Lys at 1.40. In diets devoid of NaHCO 3 , increasing Arg:Lys to 1.25 impaired BWG and FCR for broilers fed DLM, although effects disappeared when more Arg was used. Performance of birds on HMB was mostly unaffected by Arg:Lys or NaHCO 3 except when fed diets void of NaHCO 3 with Arg:Lys of 1.40, when FCR was impaired. In exp. 2, broilers were maintained at thermoneutrality (TN) reaching 20°C at 33 d. Other birds were at 31°C throughout, representing chronic heat stress (CHS), while a third group changed suddenly from 20 to 31°C at 25 d representing acute heat stress (AHS). Birds within each environment were housed in one of two rooms with eight replicates of four birds per treatment. At 25 d, birds were fed Arg:Lys of 0.95 or 1.40 with DLM supplemented at requirement. Birds fed Arg:Lys of 1.40 were also offered diets with synthetic L-methionine (L-Met). Adding L-Met to high Arg diets during CHS significantly depressed ileal digestibility of all amino acids (P < 0.05). It is concluded that chronic heat stress can affect the digestibility of amino acids, and that this effect may impact performance.Key words: Broilers, methionine, arginine, heat stress, digestibility, sodium bicarbonate Gonzalez-Esquerra, R. et Leeson, S. 2006. Incidence de la source d'arginine:lysine sur la digestibilité des acides aminés et réaction aux électrolytes des aliments chez les poulets de chair soumis à un stress thermique chronique ou aigu. Can. J. Anim. Sci. 86: 263-271. Les auteurs ont imaginé deux expériences pour vérifier l'incidence de la source d'arginine:lysine, du NaHCO 3 et de la méthionine sur la digestion des acides aminés et le rendement des poulets de chair soumis à un stress thermique. Dans le cadre de la première expérience, ils ont servi une ration de maïs et de soja contenant un ratio d'arginine:lysine (Arg:Lys) de 1,10, 1,25 ou 1,40 aux volatiles du 21 e au 42 e jour. La ration était enrichie d'acide 2-hydroxy-4-(méthylthio)-butanoïque (HMB) ou de DL-méthionine (DLM) assortie de NaHCO 3 à 0 ou à 1,04 %. L...

Effect of Adding L-Arginine to Broiler Diets on Physiological Performance

“…Additionally, [45] indicated that creatine levels in the muscles could be a criterion for evaluating arginine needs. According to [46], broilers exposed to low temperature produced creatine, as shown by the decreased levels of creatine and creatinine in the feces, but they did not increase in the muscles when exposed to heat. This suggests that broilers reared in high-temperature environments may require more L-Arginine for nitric oxide (NO) production [47].…”